title: Encoding immunological memory in the initiation of B-cell receptor signaling.
abstract: In one of the earliest events in the initiation of antigen-driven antibody responses, naïve, IgM-, and IgD-expressing B cells enter germinal centers where they irreversibly isotype switch to the expression of predominately IgG B-cell receptors (BCRs). The IgG-expressing B cells then undergo rounds of antigen-driven selection, ultimately exiting germinal centers as IgG-expressing memory B cells or plasma blast. This early switch from IgM to IgG begs the question: Of what advantage to the memory response is the B cell's expression of an IgG BCR? Despite convincing evidence that the expression of IgG BCRs is essential for antibody memory responses in vivo, the molecular basis of this requirement is only incompletely understood. Here we describe intrinsic features of IgG BCRs that endow memory B cells with the ability to rapidly and efficiently initiate signaling. Remarkably, efficient signaling is mediated through the cytoplasmic tail of the membrane IgG that binds to synapse associated protein 97, a member of a large family of proteins that are best studied for their role in regulating receptor signaling in neuronal synapses. These findings underscore an interesting parallel in the mechanisms at play in encoding immunological memory and memory in the nervous system.
authors.affiliation: Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland 20852 spierce@nih.gov.
authors.forename: Susan K
authors.initials: SK
authors.lastname: Pierce
authors.affiliation: MOE Key Laboratory of Protein Science, School of Life Sciences, Tsinghua University, Beijing 100084, China Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, China.
authors.forename: Wanli
authors.initials: W
authors.lastname: Liu
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D000941:Antigens / Q000378:metabolism; D001402:B-Lymphocytes / Q000166:cytology*; D002462:Cell Membrane / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D006801:Humans; D007072:Immunoglobulin D / Q000276:immunology; D007074:Immunoglobulin G / Q000737:chemistry / Q000276:immunology; D007075:Immunoglobulin M / Q000276:immunology; D007156:Immunologic Memory; D051379:Mice; D017452:Receptors, IgG / Q000378:metabolism; D015398:Signal Transduction / Q000276:immunology
chemical_list: D000941:Antigens; D007072:Immunoglobulin D; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D017452:Receptors, IgG